WTB -- SBP Keystone Kustomags Center Caps

I just got the SBP Keystones that were on my D/Dart back in the early 70's. Unfortunately, the fronts are missing the center caps with the large "K" and KEYSTONE on them. I believe the inside measures about 2 7/8" and they may have a 3 pronged, screw in retainer. I am looking for 2 in decient condition.

PM me if you can help me out. Any help in finding a pair would be appreciated.

Alan